JP4205841B2 - Reaction method using heterogeneous catalyst and reaction apparatus thereof - Google Patents

Description

＜原料アルコール＞
メタノール、エタノール、プロパノール、ブタノール、イソブタノール、ターシャリブチルアルコール、２エチルヘキシルアルコールなどが使用できる。
【００３１】
＜原料酸＞
（メタ）アクリル酸が使用される。
＜原料アルキレンオキシド＞
エチレンオキシド、プロピレンオキシド、ブチレンオキシド、スチレンオキシドなどが使用できる。
本発明の反応方法は、２段階以上に分けて行ってもよい。例えば、ある程度まで反応が進行した反応後の反応液を前述のようにして抜き出し、抜き出された反応後の反応液をさらに同様の方法で反応させることにより、反応率や選択率を向上させることができる。
【００３２】
〔反応装置〕
本発明の反応装置は、前記の不均一触媒粒子を用いた反応において使用される装置である。固定床反応装置と流動床反応装置の両方が適用できる。攪拌器を有する槽型の反応器と液抜きラインとを備える。反応器と液抜きラインの間に固液分離機能を有する線状スクリーンを配置する。線状スクリーンは、不均一触媒粒子を実質的に通過させない隙間幅を有する。
線状スクリーンはスクリーン面が反応器の内側で下向きになるように、反応器の側壁に取り付けられていることが好ましい。このように、スクリーン面を下向きになるように設置することにより、不均一触媒粒子による目詰まりを効果的に防止することができる。
【００３３】
さらに、流動床反応装置の場合、線状スクリーンは、固液分離の際の不均一触媒粒子を含むスラリー状反応液の流動を大きく妨げないように設置されていることが好ましい。
本発明の反応装置は、前記液抜きラインを複数備え、各液抜きラインが別々の線状スクリーンを介して前記反応器に繋がれていることが好ましい。
線状スクリーンは、反応液の流動経路中に設置することで、固液分離の効率がよくなりトラブルも少なくなる。具体的な設置場所については特に限定されない。
【００３４】
例えば、槽の底部にノズルをつけ、このノズルの中に線状スクリーンを埋め込んでもよいし、ノズルからはみ出すような形態で線状スクリーンを取り付けることもできる。槽の底部に板状のスクリーンを取り付けることもできる。線状スクリーンを埋め込んだり一部をはみ出して取り付けたノズルを、槽の側部に取り付けることもできる。槽の上部に抜き出し管を取り付け、その先端に線状スクリーンを設けておくこともできる。
但し、流動床反応装置の場合、樹脂の滞留部に線状スクリーンを設置すると、その滞留部分での副反応が進んだり、重合物等の固形物によるトラブルが発生し易い。そのため、各攪拌や循環によって液が流動している部分に線状スクリーンを配置するのが好ましい。
【００３５】
滞留部分に線状スクリーンを設置した場合、不均一触媒の粒子がスクリーン表面に付着し、その分だけ濾過の差圧が上がるというデメリットがあるのに対し、流動部分の場合には、濾過の差圧が上昇しない。これは、不均一触媒の粒子が常に洗い流され、表面に蓄積しないことによると考えられる。不均一触媒の滞留による副反応や重合などのトラブルも解消される。
液が流動状態であれば、槽の中にすっぽりと入る籠を線状スクリーンで作製しておき、この籠の中に不均一触媒および攪拌器をいれて攪拌しながら反応させることもできる。
【００３６】
固定床反応装置の場合も、基本的な構造は流動床反応装置と共通している。線状スクリーンの構造についても同様の技術が適用できる。反応器を横断する平坦な面を構成するように線状スクリーンを配置しておくことができる。線状スクリーンは横断面の全体あるいは一部に設けることができる。
線状スクリーンの配置は、固定床反応装置の反応器内での液流れ方向に対し、垂直な断面に対して均等な流れになるように設置するのがよい。例えば、筒状スクリーンであれば、液流れ方向に垂直な断面に対して３個／ｍ² 以上を均等に配置するのがよい。３個／ｍ² 未満の場合は、触媒層内に液の滞留部分が生じたり、重合物等が生成し易く、スクリーンを詰まらせたり、反応効率の低下を招くので好ましくない。
【００３７】
固定床反応装置の反応器には、不均一触媒が固定充填される。不均一触媒の充填方法や充填条件は、通常の反応方法と同様に行える。
反応液の流通は、反応器の下部側から上部側へと上昇流にすることもできるし、上部側から下部側への下降流にすることもできる。エステル化反応やエステル交換反応のように軽沸分離を行う反応蒸留の場合は上昇流が好ましい。詰まり防止には下降流のほうが好ましい。
反応器のうち、線状スクリーンに隣接する位置には比較的大径の不均一触媒粒子を配置し、線状スクリーンから離れた位置には比較的小径の不均一触媒粒子を配置しておくことができる。比較的大径の不均一触媒粒子は線状スクリーンの隙間を通過し難い。比較的小径の不均一触媒粒子は、反応効率が良好である。比較的大径の不均一触媒が比較的小径の不均一触媒粒子の通過を防ぐスクリーンとしての機能を果たす。
【００３８】
反応器の底部側に平坦な線状スクリーンが配置されている場合には、線状スクリーンの上部空間に比較的大径の不均一触媒粒子を一定の深さで充填し、その上の空間に比較的小径の不均一触媒粒子を充填することができる。
上記２種類の不均一触媒粒子の粒径比として、比較的小径の不均一触媒粒子の粒径を、比較的大径の不均一触媒粒子の粒径の０．８倍程度に設定することができる。比較的大径の不均一触媒粒子の粒径を線状スクリーンの隙間幅の１．１〜３０倍に設定し、比較的小径の不均一触媒粒子の粒径を線状スクリーンの隙間幅の１．０〜１５倍に設定することができる。
【００３９】
さらに、線状スクリーンと隣接する位置には、触媒機能を有しない比較的大径の粒子を配置しておき、その外側に比較的小径の不均一触媒粒子を配置しておくこともできる。触媒機能を有しない粒子の具体例として、ステンレス鋼などが使用できる。
反応器のうち、反応液が供給される側には、不均一触媒粒子の逆流を防いだり、反応液の分散を良好にするために、メッシュ状などの分散板を配置しておくことができる。反応液の分散は、不均一触媒の充填層の水平断面に対し、出来るだけ均一であるのが好ましい。
【００４０】
下降流の場合は、不均一触媒粒子の逆流対策は必ずしも必要ない。このとき、反応液の分散を良好にするための分散板は、必ずしも全面をおおう必要はない。全面または一部に配置された多孔板であってもよいし、傘状の多孔板であってもよい。メンテナンスを考えて比較的小さなものにしておくこともできる。通常の分散方法を適用して不均一触媒粒子上に液が分散されていれば、分散板の形状や構造については特に限定されない。
〔反応装置の具体例〕
以下に、前記のイオン交換樹脂を用いた反応において使用される、本発明の反応装置について、図面を用いて説明する。
【００４１】
＜固定床反応装置（１）＞
図１(a) に示す反応装置は、固定床反応装置である。
断面円形の筒状をなし、上下端がドーム状に塞がされた反応器１０は、上端には反応液４０の供給口１２を備え、下端には反応後の反応液を取り出す液出し口１４を有している。
反応器１０の内部空間で上部近くには、メッシュ状の分散板１６が配置され、底部近くには仕切り板１８が配置されている。分散板１６と仕切り板１８の間の空間に不均一触媒粒子３０が充填されている。仕切り板１８には、筒形の線状スクリーンを有する固液分離器２０が配置されており、反応液４０は固液分離器２０を通過して、仕切り板１８の下方の空間へと送りだされる。
【００４２】
不均一触媒粒子３０は、仕切り板１８および固液分離器２０に近い下部側の一定深さについては、比較的大径の不均一粒子３４が充填されている。固液分離器２０は比較的大径の不均一粒子３４に埋まった状態である。比較的大径の不均一粒子３４の上方には比較的小径の不均一粒子３２が充填されている。
不均一触媒粒子３０が充填された反応器１０に反応液４０を供給することで、反応液４０は分散板１６で反応器１０の全面に均等に拡げられ、反応器１０内を下降しながら、不均一触媒粒子３０の存在下で反応を起こす。反応後の反応液４０は、固液分離器２０で不均一触媒粒子３０と分離され、反応液４０だけが液出し口１４から取り出される。
【００４３】
分散板１６がない場合、反応液４０は供給口１２の真下の反応器１０の中心部分に集中して流れるため、反応器１０の容積のうち反応に有効に利用される部分の割合が少なくなり反応性能の悪化を招き易い。特に、反応器１０の上端に近い周囲部分では反応液４０が滞留し易く、重合や副反応が起こり易い。このような問題を解消するために、分散板１６の設置が有効である。
図１(a) に示したメッシュ状の分散板１６のほか、多孔板状の分散板を用いたり、図１(b) に示すように、供給口１２の真下に傘状の分散板１７を設置したりすることもできる。複数の分散手段を組み合わせて設置しておくこともできる。
【００４４】
なお、反応器１０の真上部分に１個所だけ供給口１２を配置しておく構造のほか、反応器１０の平面形状全体に分散して複数個の供給口１２を配置しておくこともできる。
さらに、図１(c) に示すように、反応器１０の内部で供給口１２に連結され、全体が円環状をなす分散配管１３の複数個所に、短管や貫通孔からなる通液口１５を設けておけば、周方向に均等に反応液４０を分散させて供給することができる。
図示を省略するが、上記の分散配管１３と同じものを、反応器１０の下部で液出し口１４に近い側に設けておけば、固液分離器２０を通過した反応液４０を、反応器１０の全周から均等に集めて液出し口１４へと送りだすことができる。
【００４５】
図２および図３は、固液分離器２０の詳細構造を示している。
線状スクリーンを構成する線材２２が、螺旋状に巻回されて筒形をなす状態で支持されている。筒形をなす線材２２の上下には支持部材２４、２６が配置されている。中心を貫挿する支持ボルト２８で上下の支持部材２４、２６が支持されている。支持部材２６が仕切り板１８に固定されることで、固液分離器２０が取り付けられる。
図３に示すように、螺旋状に巻回された線材２２は、隣接する部分の線材２２の間に隙間２１をあけた状態で配置され、線材２２の内周側に配置され、上下の支持部材２４、２６に支持された支持軸２３に取り付けられている。線材２２の断面形状は、概略２等辺三角形をなし、外周側に幅の広い底辺が配置され、内周側に頂点が配置されている。
【００４６】
不均一触媒粒子３０を含む反応液３０が、線材２２で構成される筒形の線状スクリーンを通過しようとすると、線材２２間の隙間２１の幅Ｗよりも大きな粒径の不均一触媒粒子３０は通過を阻止され、反応液４０だけが通過することになり、固液の分離が果たされる。
図２では、線材２２で構成される線状スクリーンの下端が、支持部材２６の内側で仕切り板１８よりも低い位置に配置されている。これによって、仕切り板１８の上面位置まで確実に反応液４０を通過させて固液分離を行うことができる。仕切り板１８の上面付近における反応液４０の滞留が起こり難い。
【００４７】
線状スクリーンすなわち線材２２の下端を、仕切り板１８の上面と同じ位置もしくはそれより下に配置しておいたり、仕切り板１８よりも少し高い位置に配置しておくこともできる。但し、仕切り板１８の上方に反応液４０の滞留が出来るだけ生じないように固液分離器２０の構造を設定するのか好ましい。例えば、前記した線状スクリーンの下端と仕切り板１８の上面との間隔は１５ｍｍ以下に設定しておくことが好ましい。
図４に示す固定床反応装置は、前記実施形態とは固液分離器２０の構造が異なる。
【００４８】
反応器１０の底部近くに、水平方向の横断面の全面にわたって平坦な線状スクリーンからなる固液分離器２０が配置されている。図４(b) に示すように、反応器１０の横断面に、多数の線材２２が互いの間に隙間２１をあけて平行に配置されている。線材２２の断面形状は、前記図３と同じであり、幅の広い底面側が上部、頂点側が下部に配置されている。多数の線材２２は、裏面側に配置された支持軸２３で支持されている。
上記実施形態では、反応器１０の横断面全体が固液分離機能を果たすことになり、効率的な固液分離が行える。
【００４９】
＜流動床反応装置＞
図５に示す反応装置は、流動床反応装置である。
反応器５０の基本的な構造は前記した固定床反応装置の場合と同様である。図示しないが、反応器５０の上部には反応液４０の供給口を備えている。
反応器５０の内部に、モータなどで回転駆動される攪拌器５２が設けられている。反応器５０の下部外周には、加温あるいは冷却を行うための加熱冷却ジャット５４が設けられている。
反応器５０の下部側面には、収容筒５８の内部に収容された固液分離器２０が取り付けられている。筒形の線状スクリーンからなる固液分離器２０は収容筒５８の端面を塞ぐフランジ板５９に接続された液出し管５６に接続されている。
【００５０】
固液分離器２０は、大部分が収容筒５８の内部に配置されているとともに、先端の一部は収容筒５８よりも内側の反応器５０の内部に突き出している。
図５(b) に示すように、収容筒５８および固液分離器２０は複数台が設置されており、反応器５０の水平断面において放射方向に配置されているものと、放射方向に対して傾いた方向に配置されているものとが混在している。
流動床反応装置では、反応器５０の上部に供給された反応液４０と不均一触媒粒子３０とは、攪拌器５２で攪拌されることによって、流動状態で反応を行う。
反応液４０の一部を、固液分離器２０を経て液出し管５６へと抜き出す。このとき、反応液４０に分散している不均一触媒粒子３０は、固液分離器２０の筒形スクリーンを構成する線材２２の隙間２１は通過できないので、反応液４０だけが分離されて取り出される。
【００５１】
図６に示す実施形態は、前記実施形態とは固液分離器２０の取付構造が異なる。
図６(a) では、収容筒５８に収容された固液分離器２０の先端が、反応器５０の内周壁よりも内側に配置されている。
図６(b) では、固液分離器２０の先端が収容筒５８よりも内側に大きく突出している。また、固液分離器２０の先端側の長さＬの部分だけに線材２２による線状スクリーンが設けられている。
図６(c) では、図６(b) の構造において、収容筒５８と固液分離器２０との間の隙間が極力小さくなるように、固液分離器２０の根元側を外周に張り出している。このような構造であれば、収容筒５８と固液分離器２０の間における反応液や不均一触媒粒子の滞留をなくし、重合物の生成や副反応を防ぐことができる。収容筒５８と固液分離器２０との隙間にテフロン（商品名、フッソ樹脂）等からなるパッキン材を入れておいてもよい。
【００５２】
図７に示す実施形態は、反応器５０の底面中央に固液分離器２０を配置している。
図７(a) では、反応器５０の底面中央に上向きに固液分離器２０が配置されている。図７(b) では、反応器５０の底面中央に下向きに張り出した収容筒５８の内部に固液分離器２０が収容されている。図７(c) では、反応器５０の底面周辺部に固液分離器２０が配置され、固液分離器２０の一部が収容筒５８に残りの一部が反応器５０の内部空間に配置されている。線材２２からなる線状スクリーンは、収容筒５８よりも上方に配置されている。固液分離器２０の下部を太く張り出して、固液分離器２０と収容筒５８の内面との間に大きな隙間が出来ないようにしている。この構造で、固液分離器２０の長さは特に限定されるものではなく、例えば、液面近くまで延ばしておいてもよい。
【００５３】
【実施例】
以下、本発明にかかる実施例および比較例について説明するが、本発明は該実施例により何ら制限されるものではない。
〔固定床反応〕
＜実施例１＞
固定床反応装置を用いてメチルアクリレートの生成反応を行った。
生成物：メチルアクリレート
原料：アクリル酸、メタノール
反応器：固定床反応装置（図１参照）、径１４００mm、高さ２３００mm、直胴部容量３．５ｍ³ 、樹脂仕込み量２．０ｍ³
固液分離器：ジョンソンスクリーン（商品名：日揮ユニバーサル社販売）、円筒型、濾過有効部（線状スクリーン）が仕切り板よりも１０mm下まで配置されている（図２参照）、筒形スクリーンの外径５０mm、有効長さ１７０mm、線材の幅１．５mm、隙間幅０．３mm、設置数２０個（１３．０個／ｍ² ）、有効濾過面積０．５３４ｍ² （０．０２７ｍ² ／個）、開口部面積０．０８９ｍ² （０．００４４ｍ² ／個）
通過液量：通過液量１．６７ｍ³ ／ｈ、液密度９００ｋｇ／ｍ³ 、有効濾過面積通過速度０．８７ｍｍ／ｓ、開孔部通過線速５．２ｍｍ／ｓ、反応器の上部から下部への下降流
不均一触媒：ダイヤイオンＰＫ−２０８（商品名：三菱化学社製、パラトルエンスルホン酸を主成分とする多孔質タイプの陽イオン交換樹脂、５０％粒径＝約７００μｍ、１５％粒径＝約５００μｍ
−実施結果−
反応器入口組成：主原料（アクリル酸）５０％、副原料（メタノール）２０％、製品（メチルアクリレート）１５％、水５％
反応器出口組成：主原料（アクリル酸）３０％、副原料（メタノール）５％、製品（メチルアクリレート）４０％、水１０％、不純物１５％
コンバージョン３５〜４０％
１００時間後：運転上の問題なし
１０００時間後：不均一触媒粒子には問題なし。ポリマー付着はほとんどない。線状スクリーンの支持構造に微量のポリマーが付着したが簡単に除去できた。
【００５４】
＜実施例２＞
実施例１において、固液分離器のジョンソンスクリーンとして、線状スクリーンの部分が、仕切り板の上に１５mm突出する状態で配置された構造のものを用いた。線状スクリーンの下端と仕切り板の表面との間に間隔があいており、仕切り板の上に反応液が少し滞留する構造である。
−実施結果−
反応実施１０００時間後に、線状スクリーンの支持構造にポリマー付着があった。半数の線材にわずかなつまりが発生。但し、ジェット洗浄を行うことで除去できた。一部の線材はブラシ洗浄を行った。
【００５５】
＜実施例３＞
メチルメタアクリレートの生成反応を行った。実施例１と共通する条件については説明を省略する。
生成物：メチルメタアクリレート
原料：メタアクリル酸、メタノール
反応器：固定床反応装置（図１参照）、径１８００mm、高さ２５００mm、満液状態で使用。
固液分離器：ジョンソンスクリーン（商品名：日揮ユニバーサル社販売）、筒形スクリーンの外径６０mm、有効長さ１７０mm、エレメント（線材）の幅１．５mm、隙間幅０．１５mm、設置数２０個（４．８個／ｍ² ）、有効濾過面積０．６４ｍ² （０．０３２ｍ² ／個）、開口部面積０．０５８ｍ² （０．００２９ｍ² ／個）
通過液量：通過液量３．００ｍ³ ／ｈ、液密度９００ｋｇ／ｍ³ 、有効濾過面積通過速度１．３０ｍｍ／ｓ、開孔部通過線速１４ｍｍ／ｓ
不均一触媒：実施例１と同じ。
【００５６】
−実施結果−
反応温度：７０℃
反応器入口組成：主原料（メタアクリル酸）６１％、副原料（メタノール）９％、製品（メチルメタアクリレート）２７％
反応器出口組成：主原料（メタアクリル酸）４５％、副原料（メタノール）３％、製品（メチルメタアクリレート）４６％
コンバージョン２５％になるように反応温度を操作した。
４カ月後：反応温度は７９℃であり、実施例４に比べて、不均一触媒粒子の寿命延長に効果があることが確認できた。不均一触媒粒子は、４ヵ月の連続運転で運転上問題なし。ポリマー付着はほとんどない。線状スクリーンの支持構造に微量のポリマー付着が簡単に除去できた。
【００５７】
＜実施例４＞
実施例３において、固体液分離器を、実施例２の構造に変更した。具体的には、固液分離器のジョンソンスクリーンとして、線状スクリーンの部分が、仕切り板の上に１５mm突出する状態で配置された構造のものを用いた。
−実施結果−
反応温度：７０℃
反応器入口組成：主原料（アクリル酸）６１％、副原料（メタノール）９％、製品（メチルアクリレート）２７％
反応器出口組成：主原料（アクリル酸）４５％、副原料（メタノール）３％、製品（メチルアクリレート）４５％
４ヵ月後：反応温度８３℃。不均一触媒粒子は、４ヵ月の連続運転で運転上問題なし。線状スクリーンの支持構造にポリマー付着。半数の線材にわずかなつまりが発生。但し、ジェット洗浄を行うことで除去できた。一部の線材はブラシ洗浄を行った。
【００５８】
＜実施例５＞
実施例３において、不均一触媒粒子の充填条件を変更した。実施例３と共通する条件については説明を省略する。
具体的には、不均一触媒粒子を分級し、粒径７００〜１２００μｍの大粒部（全体の５％）と、粒径３００〜７００μｍの小粒部（全体の９５％）に分割した。図１に示すように、反応器１０の底部側で固液分離器２０よりも少し高い位置まで大粒部３４を充填したあと、その上に、小粒部３２を充填した。
−実施結果−
４ヵ月後：反応温度７７℃。不均一触媒粒子は、４ヵ月の連続運転で運転上問題なし。ポリマー付着はほとんどない。極微量の付着ポリマーも簡単に除去できた。
【００５９】
＜比較例１＞
実施例２において、固液分離器にワイヤメッシュストレーナを用いた以外は、同じ条件を採用した。
固液分離器：ワイヤメッシュストレーナ、円筒、５０メッシュ、濾過有効部が仕切り板の１５mm上に配置される。
−実施結果−
１００時間後：経時的に反応率、選択率が低下していき、圧力損失が上昇する傾向であった。
【００６０】
約５００時間で運転が困難になったので、点検を行ったところ、不均一触媒粒子の微細なものがストレーナのメッシュに詰まっていた。粘性物、ポリマーの付着が多かった。メッシュの交換が必要であった。ストレーナの支持構造にもポリマーが付着していた。
〔流動床反応〕
＜実施例６＞
流動床反応装置を用いて、２エチルヘキシルアクリレートの生成反応を行った。
【００６１】
生成物：２エチルヘキシルアクリレート
原料：アクリル酸、２エチルヘキサノール
反応器：流動床反応装置（図５参照）、脱水充填塔１００φ付き、径５００ｍｍ、ステンレス製１００リットル、仕込み量〔反応液＋不均一触媒粒子７０リットル、不均一触媒粒子１８リットル（乾燥状態）〕、ジャケット加熱／蒸気投入。
固液分離器：ジョンソンスクリーン（商品名：日揮ユニバーサル社販売）、円筒型、反応器の底部外周に取付、筒形スクリーンの外径３４mm、有効長さ６０mm、エレメント（線材）の幅１．５mm、隙間幅０．１５mm、設置数１個（３．１個／ｍ² ）、有効濾過面積０．００６４ｍ² 、開口部面積０．０００５８ｍ² 、図６(c) に示す構造の固液分離器を９０°回転させて上向き姿勢で設置。
【００６２】
通過液量：通過液量０．０３９ｍ³ ／ｈ、液密度９００ｋｇ／ｍ³ 、有効濾過面積通過速度３．１７ｍｍ／ｓ、開孔部通過線速１８ｍｍ／ｓ、反応器の上部から下部への下降流。
攪拌器：ファウドラ翼、翼径比０．７、翼先端速度４ｍ／ｓ
不均一触媒：実施例１と同じ。
−実施結果−
反応器圧力：７０ｍｍＨｇ
反応器入口組成：主原料（アクリル酸）４９％、副原料（２エチルヘキサノール）３５．６％、製品（２エチルヘキシルアクリレート）１４．２％、水０．１％。反応器に２３．５ｋｇ／ｈおよび塔頂から１３．２ｋｇ／ｈのアルコールを供給、塔頂より主原料に対して０．０５％のフェノチアジンを投入した。
【００６３】
反応器出口組成：主原料（アクリル酸）１３．２％、副原料（２エチルヘキサノール）２５．７％、製品（２エチルヘキシルアクリレート）５９．６％、水０．４％で、反応液は３４．８ｋｇ／ｈであった。留出タンクでは、水相１．７ｋｇ／ｈ、油相０．１８ｋｇ／ｈを抜き出した。
コンバージョン：アクリル酸で６０％、アルコールで５８％
選択率：アクリル酸で９８．４％、アルコールで９８．５％
不純物：ダイマー酸２エチルヘキシル０．２６％等
１５０時間後点検、ポリマーはなかった。
【００６４】
１０００時間後：スクリーンの隙間に樹脂が詰まっていた。ポリマーの付着はなし。問題なし。
＜実施例７＞
ヒドロキシプロピルアクリレートの生成反応を行った。
生成物：ヒドロキシプロピルアクリレート
原料：アクリル酸、プロピレンオキサイド
反応器：不均一触媒粒子４８リットル（湿潤状態）を仕込み、ジャケットに冷水を流して冷却した以外は、実施例６と同じ。
【００６５】
固液分離器：ジョンソンスクリーン（商品名：日揮ユニバーサル社販売）、円筒型、反応器の底部外周の反応液の流動部分に取付（図６(b) 参照）、筒形スクリーンの外径３４mm、有効長さ３０mm、エレメント（線材）の幅１．５mm、隙間幅０．１５mm、設置数１個（３．１個／ｍ² ）、有効濾過面積０．００３２ｍ² 、開口部面積０．０００２９ｍ² 。
通過液量：通過液量０．０３１ｍ³ ／ｈ、液密度９００ｋｇ／ｍ³ 、有効濾過面積通過速度２．７ｍｍ／ｓ、開孔部通過線速３０ｍｍ／ｓ。
攪拌器：実施例６と同じ。
【００６６】
不均一触媒：ダイヤイオンＰＫ−３１６（商品名：三菱化学社製、アミン系の陰イオン交換樹脂、５０％粒径＝約７００μｍ、１５％粒径＝約４５０μｍ）
−実施結果−
反応温度：８０℃
反応器入口組成：主原料（アクリル酸）４５重量％、副原料（プロピレンオキサイド）５５重量％。
滞留時間：１時間になるように原料投入。
コンバージョン：８０％
１００時間後：異常なし
１０００時間後：ポリマーの付着なし
＜実施例８＞
２ヒドロキシエチルアクリレートを用いて固液分離を行った。
【００６７】
反応器：ステンレス製２０リットルの容量で、不均一触媒６０％仕込みにした以外は実施例７と同じ。
固液分離器：実施例７と同じ。
通過液量：通過液量０．００９５ｍ³ ／ｈ、液密度１０５０ｋｇ／ｍ³ 。
攪拌器：パドル（３枚）、翼径比０．４、翼先端速度１．５ｍ／ｓ。
不均一触媒：実施例７と同じ。
−実施結果−
操作温度：６０℃
１００時間後：異常なし
１０００時間後：異常なし、安定した運転、目詰まりなし。
【００６８】
＜比較例２＞
実施例６において、固液分離器に８０メッシュの金網を用いた以外は、同じ条件を採用した。
固液分離器：８０メッシュの金網（径１００mm）を反応器の底部の抜き出し管に取り付けた。メッシュ線材の幅０．１５mm、隙間幅０．１７mm、開口率２５％、有効濾過面積０．００７９ｍ² 、開口部面積０．００１９６ｍ² 。
通過液量：通過液量０．０３９ｍ³ ／ｈ、液密度９００ｋｇ／ｍ³ 、有効濾過面積通過速度１．４ｍｍ／ｓ、開孔部通過線速５．５ｍｍ／ｓ（、反応器の上部から下部への下降流。
【００６９】
攪拌器、不均一触媒：実施例６と同じ。
−実施結果−
１５０時間後、樹脂が目詰まりし、差圧が上昇傾向になったので運転を停止し点検を行った。
メッシュに不均一触媒が目詰まりを起こしていた。また、ポリマーの付着による目詰まりも多かった。固液分離器を十分に洗浄してから復帰させる必要があった。
＜比較例３＞
比較例２と同様に、固液分離器に８０メッシュの金網を用いた以外は、実施例６と同じ条件を採用した。
【００７０】
固液分離器：８０メッシュの金網（径１００mm）を円筒状にして、反応器の底部の外周部に取り付けた。取付位置は攪拌器の翼径の５０％より外側。筒形メッシュの外径３４ｍｍ、有効長さ６０ｍｍ、メッシュ線材の幅０．１５mm、隙間幅０．１７mm、設置数１（３．１４個／ｍ² ）、有効濾過面積０．００６４ｍ² 、開口部面積０．０００１６ｍ² 。
通過液量：通過液量０．０３９ｍ³ ／ｈ、液密度９００ｋｇ／ｍ³ 、有効濾過面積通過速度１．７ｍｍ／ｓ、開孔部通過線速７ｍｍ／ｓ、反応器の上部から下部への下降流。
【００７１】
攪拌器、不均一触媒：実施例６と同じ。
−実施結果−
５００時間後：メッシュに樹脂が少し目詰まりを起こしていた。少量のポリマー付着があったので、洗浄を行った。
＜比較例４＞
実施例７と同じ生成反応を、反応器と沈降槽とを組み合わせて実施した。
反応器には固液分離器を設けず、反応器から抜き出した反応液と不均一触媒粒子とのスラリー液を、４０ｍｍφ×１００ｍｍ高さの重量沈降槽に送って、上澄み液を抜き出した。沈降槽も冷却ジャケット（１リットル／時間で循環）で冷却した。
【００７２】
−実施結果−
３時間後、沈降槽の温度上昇傾向が認められた。循環ポンプの異常がみられたので停止させた。沈降槽に、ポリマーと固まった不均一触媒とがみられた。
【００７３】
【発明の効果】
本発明によれば、不均一触媒を用いた反応方法において、不均一触媒粒子と反応液との分離に際し、副反応や重合を防止し、不均一触媒粒子の目詰まりによる不安定な運転を回避しつつ、コンパクトな装置を用いて、不均一触媒粒子と反応液との分離を確実に効率よく行うことができる。
特に、不均一触媒粒子と反応液との分離を行う線状スクリーンは、幅方向に比べて長さ方向に十分に広い隙間を有しているため、隙間幅を狭くしても反応液の通過を阻害することが少ない。また、粘性や付着性の高いポリマーが生成される反応であっても、線状スクリーンの隙間に詰まったり付着してしまうことが少ない。
【図面の簡単な説明】
【図１】 本発明の実施形態を表す固定床反応装置の断面図(a) および要部断面部(b) (c)
【図２】 固液分離器の拡大断面図
【図３】 線状スクリーンの拡大断面図
【図４】 流動床反応装置の垂直断面図(a) および水平断面図(b)
【図５】 別の実施形態を表す概略構造図(a) および水平断面構造図(b)
【図６】 別の実施形態を表す概略構造図
【図７】 別の実施形態を表す概略構造図
【符号の説明】
１０、５０ 反応器
１２ 供給口
１４ 液出し口
１５ 通液口
１６ 分散板
１８ 仕切り板
２０ 固液分離器
２１ 隙間
２２ 線材
３０ 不均一触媒粒子
４０ 反応液
５２ 攪拌器[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a reaction method using a heterogeneous catalyst such as ion exchange resin particles as a catalyst, and a reaction apparatus used in this method. Specifically, for example, a reaction for generating (meth) acrylate using (meth) acrylic acid is targeted.
[0002]
[Prior art]
As a reaction method for performing a reaction in a liquid phase using an ion exchange resin as a catalyst, a method using a reactor in which an ion exchange resin is fixed and filled (fixed bed reaction method), or suspending an ion exchange resin in a reaction solution. A method (fluidized bed reaction method) is known in which a reaction is performed while being dispersed, and a reaction solution and an ion exchange resin are separated after the reaction.
The fluidized bed reaction method is preferable in that the reaction efficiency can be improved.
In JP-A-49-54326, gas is introduced from the bottom of a reactor to suspend and disperse the ion exchange resin in the reaction solution, and the ion exchange resin and the reaction solution are separated using a catalyst separation device including a filter. A method of separating the two has been proposed. JP-A 63-17784 discloses that an ion exchange resin is suspended and dispersed in a reaction solution using a stirrer, and an ion exchange resin and an 80 mesh metal net provided at the bottom of the stirring tank are used. A method for separating the reaction solution has been proposed.
[0003]
[Problems to be solved by the invention]
Among the conventional methods described above, in the fluidized bed reaction method, when the ion exchange resin and the reaction liquid are separated using a filter or a wire mesh, depending on the ion exchange resin crushed during the reaction or a polymer by-produced during the reaction, etc. Filters and wire meshes are clogged, making long-term operation difficult, and crushed ion exchange resins are likely to leak.
For example, in the case of a reaction in which (meth) acrylic acid and alcohols are reacted to produce (meth) acrylate, there is a problem that further hydrolysis occurs due to the leaked ion exchange resin. In addition, when the above reaction is continuously performed, there is a problem that the amount of effective resin decreases with time due to a drift caused by clogging or the like, and the reaction rate decreases. As an effective means for separating the ion exchange resin from the reaction solution, a sedimentation method can be considered. However, this method has a drawback that the apparatus becomes large-scale and the time required for the separation becomes long.
[0004]
Moreover, in the conventional means for separating the ion exchange resin and the reaction liquid, a staying part of the ion exchange resin and the reaction liquid occurs during the separation, so that the reaction further proceeds during the stay. However, in this case, since the liquid and the resin are not flowing, the reaction becomes non-uniform, and the side reaction is preceded to increase impurities.
In particular, in the case of a reaction that generates heat, such as a reaction in which an alkylene oxide and (meth) acrylic acid are reacted to form a hydroxyalkyl (meth) acrylate, an abnormal temperature rise occurs because it is difficult to remove heat in the staying portion. It will be. Polymerization of (meth) acrylic acid as a raw material or hydroxyalkyl (meth) acrylate as a target product is likely to occur at a portion where the temperature is high, and as a result, problems such as clogging occur.
[0005]
Further, in the fixed bed reaction method, the wire mesh is easily clogged by a resin having a small particle diameter or a by-product polymer. In the clogged portion, the liquid hardly flows and the reaction solution stays, and the portion that performs an effective reaction decreases. When the staying part is generated in the reactor, not only the reaction rate is decreased and the side reaction is increased, but also polymerization of raw materials and products is accelerated, which may make operation difficult.
In addition to the reaction using an ion exchange resin, the same problem occurs in a method of performing a reaction in a liquid phase using various heterogeneous catalysts.
The object of the present invention is to prevent side reactions and polymerization in the separation of the heterogeneous catalyst and the reaction liquid, avoiding unstable operation due to clogging of the heterogeneous catalyst, and using a compact device, It is to ensure that the catalyst and the reaction liquid can be separated efficiently.
[0006]
[Means for Solving the Problems]
  The reaction method using the heterogeneous catalyst according to the present invention is as follows.A cylindrical reactor having a circular cross section, and a cylindrical screen formed by spirally winding wire rods and having a gap width that does not substantially allow non-uniform catalyst particles to pass through, The linear screen is placed on the partition plate arranged at the bottom of the space for filling the heterogeneous catalyst particles in the reactor so that the gap between the gap through which the reaction solution passes and the top surface of the partition plate is 5 mm or less. A method using a fixed bed reactor arranged and passing the reaction solution from the upper part to the lower part of the reactor filled with heterogeneous catalyst particles,Filling the reactor with heterogeneous catalyst particles (-a), reacting the reaction solution supplied to the reactor in the presence of the heterogeneous catalyst particles, and the heterogeneity. The reaction solution containing the catalyst particles after the reactionSaidLinear screenFrom outside to insideA step (b) of extracting the reaction solution separated from the heterogeneous catalyst particles from the reactor, and in the step (-a), the position adjacent to the linear screen on the upstream side is relatively large. A heterogeneous catalyst particle having a diameter is arranged, and a heterogeneous catalyst particle having a relatively small diameter is arranged at a position away from the linear screen.It is characterized by.
  According to the present inventionFixed floorThe reactor is a reactor used in the reaction method of the present invention, and contains heterogeneous catalyst particles and a reaction solution.Circular in cross sectionA heterogeneous catalyst which is disposed between a tank-type reactor, a drain line connected to the reactor and for taking out a reaction liquid after reaction, and a space for accommodating the reaction liquid in the reactor and the drain line; A linear screen having a gap width that does not substantially allow particles to pass therethrough, a relatively large-diameter heterogeneous catalyst particle is disposed at a position adjacent to the linear screen, and at a position away from the linear screen. Place heterogeneous catalyst particles with relatively small diametersIt is characterized by.
  The present invention is intended for a liquid phase reaction, and not a method for performing a reaction in a gas phase.
[0007]
The “linear screen having a gap width that does not substantially allow the passage of the heterogeneous catalyst particles” means that the heterogeneous catalyst particles used industrially always have a particle size distribution, and thus achieve the effects of the present invention. This means that there may be non-uniform catalyst particles passing through the linear screen within a range that does not affect the above.
Usually, the gap width of the linear screen is set so that the ratio of particles passing through the linear screen is 5% by volume or less, preferably 2% or less, and most preferably 0.3% or less.
Further, in the volume-based particle size distribution, the particle size at the time when it becomes 15% on the small particle size side is defined as 15% particle size, and the gap width of the linear screen may be set smaller than the 15% particle size. It is valid. The lower limit of the gap width of the linear screen can be set to the larger of 1/25 of 15% particle size or 0.05 mm. When the gap width is smaller than the above dimensions, the screen is easily clogged even if a small amount of fine particles of the catalyst particles is small, and it is difficult to clean the screen clogged with such fine fragments.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail.
[Average particle size]
In the present invention, heterogeneous catalyst particles having an average particle diameter of 0.1 to 3 mm can be used. The average particle size is defined by a 50% particle size, and the measurement method is the same as the 15% particle size described later, but the evaluation criterion is set to 50%. When the particle diameter of the heterogeneous catalyst particles exceeds 3 mm, the contact area with the reaction liquid is reduced, and the reaction efficiency is lowered. On the other hand, when the particle diameter of the heterogeneous catalyst particles is less than 0.1 mm, clogging is likely to occur when the heterogeneous catalyst particles and the reaction liquid are separated. The average particle diameter of the heterogeneous catalyst particles is more preferably 0.3 to 2 mm. The particle diameter of the heterogeneous catalyst particles is a micrometer, a caliper, an ultrasonic measurement device, a measurement using an optical microscope, a method of acquiring a microscope image and calculating it with an image processing device and an arithmetic processing device, or the like, or It can be measured by classification with a sieve.
[0009]
[15% particle size]
When the particle diameter of the heterogeneous catalyst particles is defined with the above-mentioned 15% particle diameter, it can be measured by the following method.
For example, in the case of wet particles, the volume of a state in which resin particles are immersed and settled in a liquid having the same composition as that of a wet solvent using a graduated cylinder (specifically, Measure the volume when the volume no longer decreases while tapping the bottom. While gently flowing the same particles together with the same liquid, the product is separated into a pass product and an on-product using a measurement sieve with precisely defined sieves. Collect pass products and ON products, and measure the volume with a graduated cylinder. Here, if the pass product is 15% by volume or less, it can be seen that the 15% particle size of the particles is larger than the opening of the sieve. By changing the sieve and repeating the above measurement, the particle size of 15% can be measured.
[0010]
If it is difficult to handle at the same composition or temperature as the wet solvent, it may be measured by changing the solvent such as water, but it is necessary that the resin volume change is ± 10% or less by changing the solvent. is there.
When the volume (volume) change between the wet state and the dry state is ± 10% or less, the volume of the heterogeneous catalyst particles may be defined by dry particles. In this case, it is not necessary to use a liquid, and the size of the particles relative to the sieve may be evaluated depending on whether or not the pass product is 10% by volume or less when separated using a vibrating sieve.
[Heterogeneous catalyst]
The heterogeneous catalyst used in the present invention is not particularly limited.
[0011]
For example, all commercially available ion exchange resins such as strong acid type or weak acid type cation exchange resin, strong base type or weak base type anion exchange resin may be mentioned. In particular, when used for an exothermic reaction, a heat-resistant resin is suitable. Examples of the heterogeneous catalyst other than the ion exchange resin include ceramics such as silica, alumina, titania, activated carbon, and the like containing metals, noble metals and oxides thereof.
The shape of the ion-exchange resin particles is not particularly limited, and for example, spherical, elliptical, cylindrical pellets, pyramids, cones, needles, etc. can be used. In view of the fact that the resin particles are easily fluidized and the resin is not crushed by the collision of the resin particles, a spherical shape or a nearly elliptical spherical shape is preferable.
[0012]
[Cation exchange resin]
As the cation exchange resin, a strongly acidic cation exchange resin can be used. Porous or gel type resins can be used.
Specific examples of porous type strongly acidic cation exchange resins include MSC-1 (above, manufactured by Dow), PK-208, PK-212, PK-216, PK-220, PK-228 (above, Mitsubishi Chemical). Manufactured by Amberlist-16, IR-116, IR-118, IR-122, C-26, C-26TR, C-264, C-265 (above, manufactured by Rohm and Haas), SPC- 108, SPC-112 (manufactured by Bayer), KC-470 (manufactured by Sumitomo Chemical), and the like.
[0013]
Specific examples of the gel type include HCR-S, HCR-W2, HGR-W2 (manufactured by Dow), SK-1B, SK-106, SK-110 (Mitsubishi Chemical).
[Anion exchange resin]
As the anion exchange resin, either a strong basic anion exchange resin or a weak basic anion exchange resin can be used. When used in the addition reaction of alkylene oxide in the present invention, a strongly basic anion exchange resin is preferably used. Moreover, any of a gel type, a porous type, a macroporous type, a primary crosslinking type, and a secondary crosslinking type can be used.
[0014]
Specific examples of the gel type include SBR, SBR-PC, SAR (above, manufactured by Dow), IRA-400, A-132, ES-137, A-101D, A-147, A-104, A -109, A-102D (above, manufactured by Rohm and Haas), SA10A, SA20A (above, manufactured by Mitsubishi Chemical Corporation), and the like.
Specific examples of the porous type include IRA-904, IRA-411, IRA-402, IRA-402BL (manufactured by Rohm and Haas).
Specific examples of the macroporous type include MSA-1, MSA-2 (manufactured by Dow), IRA-900, IRA-938, IRA-958, A-26, A-27, A-161, A-162 ( As mentioned above, PA306, PA308, PA312, PA316, PA318, PA406, PA408, PA412, PA416, PA418, WA30, WA20, WK10 (above, manufactured by Mitsubishi Chemical Corporation) and the like can be mentioned.
[0015]
Weakly basic anion exchange resins include weakly basic resins in which the type of amine used as a functional group is dimethylamine or the like.
Examples of the strongly basic anion exchange resin include (I) type in which the type of amine used as a functional group is a trimethylammonium group or the like, and (II) type that is a dimethylethanolammonium group or the like.
[Suspension dispersion]
In the present invention, as the fluidized bed reaction method, the reaction can be carried out by suspending and dispersing the heterogeneous catalyst particles in the reaction solution. As a result, the number of times of contact between the heterogeneous catalyst particles and the reaction liquid can be increased to improve the reaction efficiency, and at the same time, the heat removal effect when using a jacket and / or a coil or the like in the reaction accompanied by heat generation. Can also be expected. When it is difficult to remove heat with only a jacket, it is effective to increase the heat removal capability using a coiled coil, a hairpin coil, or the like.
[0016]
The means for suspending and dispersing the heterogeneous catalyst particles in the reaction solution is not particularly limited. For example, a method using a stirrer equipped with paddle blades, fowler blades, Max blend blades, anchor blades, etc., a method of introducing gas from the bottom of the reactor, or a method of using these in combination can be employed.
[Amount of charged heterogeneous catalyst particles]
In the case of the fluidized bed reaction method, it is preferable that the charged amount of the heterogeneous catalyst particles is 0.05 to 1.0 times based on the apparent volume with respect to the total charged amount.
When the charged amount of the heterogeneous catalyst particles exceeds 1.0 times based on the apparent volume with respect to the total charged amount, it becomes difficult to suspend and disperse the particles, and the stirring and mixing becomes uneven, which is not preferable. Further, the particle crushing in the vicinity of the stirrer proceeds excessively, which is not preferable in terms of shortening the catalyst life. Detrimental effects such as clogging of clogged particles in the subsequent process while the equipment is in operation. There is also a tendency for harmful side reactions to increase.
[0017]
When the volume of the heterogeneous catalyst changes with time, the charging amount is set to be as small as possible in consideration of the volume change.
When the charged amount is less than 0.05 times, the side reaction proceeding without a catalyst in the liquid increases as compared with the main reaction proceeding on the catalyst surface, which is not preferable. Further, it is necessary to increase the stirring for promoting the reaction, and the catalyst is easily crushed.
[Wing tip speed]
When the reaction vessel is equipped with a stirrer and the reaction is performed while stirring the reaction liquid, the blade tip speed (TIP SPEED) of the stirrer blade of the stirrer is 0.1 to 10 m / s, preferably 0.3 to 5 m / s. It is desirable to set it to s.
[0018]
The blade tip speed can be obtained by the following equation from the rotation diameter (span) of the tip of the stirring blade and the stirring rotation speed.
Blade tip speed (m / s) =
Rotation diameter (span) (m) x stirring rotation speed (rpm) x π / 60
When the blade tip speed exceeds 10 m / s, the equipment cost for stirring and the running cost of power increase, which is not economical. In addition, an excessive force is applied to the heterogeneous catalyst particles, and the catalyst life is shortened by damaging or crushing the heterogeneous catalyst particles. It is not preferable.
[0019]
On the other hand, if the blade tip speed is less than 0.1 m / s, the heterogeneous catalyst particles are less likely to float in the reaction solution, the partial reaction becomes nonuniform, and the local temperature and concentration are not uniform. As a result, the side reaction increases, which is not preferable for the reaction. Further, in the heat removal of the reaction heat, since the heat removal efficiency is lowered, it is not preferable for controlling the reaction temperature.
[Reaction temperature]
The reaction temperature is preferably 15 to 120 ° C.
When the reaction temperature exceeds 120 ° C., dimer acid, oligomers and the like increase, esterified products thereof are generated, and side reactions generated by high-boiling products increase, which is not preferable. In addition, troubles due to the polymer are likely to occur, which is not preferable.
[0020]
If the reaction temperature is less than 15 ° C., the cost of the cooling medium for cooling increases, which is not preferable. In addition, the reaction rate is often slow, the apparatus size is increased, and there are many disadvantages economically.
As a more preferable range of the reaction temperature, 30 to 115 ° C, further 50 to 105 ° C can be adopted.
In the present invention, the reaction conditions other than those described above are not particularly limited, and can be appropriately set according to conventional techniques.
(Solid-liquid separation)
In the reaction method of the present invention, after the reaction in the presence of the heterogeneous catalyst particles, the reaction liquid and the heterogeneous catalyst are passed by passing the reaction liquid containing the heterogeneous catalyst particles through a linear screen having a solid-liquid separation function. The particles are separated and the reaction solution is withdrawn from the reactor.
[0021]
The linear screen is arranged with a large number of wires arranged in parallel with a predetermined gap. In order to maintain the space | interval of wires, a supporting member may be arrange | positioned in the direction orthogonal to a wire. Even in this case, a substantially linear gap is formed by setting the installation interval of the support members sufficiently larger than the gap width between the wires.
What provided the linear screen whose width | variety of the clearance gap between the wire which comprises a screen is substantially smaller than the particle diameter of a heterogeneous catalyst particle is preferable. When the gap width is smaller than the particle diameter of the heterogeneous catalyst particles, the heterogeneous catalyst particles and the reaction liquid can be reliably separated. Moreover, by performing solid-liquid separation using a screen made of a wire, the heterogeneous catalyst particles are less likely to be clogged, and a stable operation can be performed for a long time. The linear screen can uniformly control the openings at regular intervals, and since there are few gaps smaller than the design size, extremely small particles contained in the heterogeneous catalyst particles have passed through the screen. It is preferable because it is difficult to cause clogging.
[0022]
It is preferable to set the ratio of the maximum value and the minimum value of the variation in the aperture of the linear screen to 2 times or less. When this ratio exceeds twice, leakage of non-uniform catalyst particles and clogging in a small gap portion are likely to occur. Preferably it sets to 1.0 to 1.5 times, More preferably, it sets to 1.0 to 1.2 times. It should be noted that the minimum value referred to here is evaluated by excluding a portion that is locally reduced due to the structure, such as a screen joint.
The linear screen is not particularly limited as long as it is made of a wire material. Specifically, for example, a net-like plate, a grid-like plate, a net-like cylinder, a coil body, and wires are arranged linearly in parallel. Examples include plate-like parallel lines. If the line screen is formed in a plate shape, the structure can be simplified and it is effective when the effective area for solid-liquid separation may be small. A cylindrical or coiled body is preferable because an effective area for solid-liquid separation can be increased and removal is easy.
[0023]
The cross-sectional shape of the wire constituting the linear screen is not particularly limited, and examples thereof include a circle, an ellipse, a triangle, a quadrangle, and a trapezoid. Preferred are a circle, an ellipse, a triangle, and a trapezoid. In the case of a triangle or trapezoid, it is preferable to place the wide bottom side on the inlet side of the solid-liquid separation because the flow path becomes wider in the liquid flow direction. If the narrow side is directed to the solid-liquid separation inlet side, the gap between the adjacent wires becomes the direction in which the flow path becomes narrower than the liquid flow direction, which is not preferable because the particles are easily clogged.
Moreover, it is preferable that the clearance gap between the wires specifically is 0.05-2 mm. The dimension in the length direction of the gap between the wires is not substantially limited as long as it is sufficiently long with respect to the gap width. For example, in the structure in which the above-described wire is wound spirally, the length of the gap can be freely extended. However, when the support member is arranged orthogonal to the wire, the interval between the support members can be evaluated as the substantial length of the gap, and can be set to a length of 5 times or more the gap width. The upper limit of the length is not particularly limited as long as the support member can be disposed within a range in which the openings are not uneven and the wire is not distorted in strength due to liquid pressure or differential pressure. The practical upper limit of the length is in the range of several tens of cm to 1 m.
[0024]
In the present invention, the means for passing the reaction liquid containing the heterogeneous catalyst particles through the linear screen and extracting the reaction liquid from the reactor is not particularly limited. For example, the pressure on the reactor side of the linear screen is not limited. However, it is preferable that the pressure be higher than the pressure on the side from which the reaction solution is extracted.
〔specific gravity〕
In the reaction method of the present invention, in the reaction liquid containing the heterogeneous catalyst particles, the specific gravity of the heterogeneous catalyst particles in the state of absorbing the reaction liquid is 0.9 to 2.0 times the specific gravity of the reaction liquid. In particular, the effect can be exhibited. In this specific gravity range, solid-liquid separation can be achieved with a compact apparatus as compared with the liquid cyclone and gravity sedimentation methods conventionally known as solid-liquid separation means. Of course, even when the specific gravity of the heterogeneous catalyst particles with respect to the specific gravity of the reaction liquid is out of the above range, the reaction method of the present invention can be applied.
[0025]
The specific gravity can be measured as follows.
For wet particles, the specific gravity is weight g excluding voids in the gaps of wet particles / volume cm in that state.^ThreeDefined in
As a specific measurement method, using a graduated cylinder, the liquid surface and particle surface of the wet sample are 10 cm.^ThreeMeasure liquid and resin accurately so that they match. Weight W of the sample₁Measure. The sample resin is wrapped in a cloth or vinyl sponge, filtered with a centrifuge for about 5 to 10 minutes, the liquid and resin are separated, quickly transferred to a weighing bottle, sealed, and the resin after removing the adhering liquid. Weight W₂Measure. The centrifuge may be performed under conditions of a diameter of about 15 cm and about 3000 rpm. The specific gravity γ of the liquid is measured in advance. From the above measurement results, the specific gravity is calculated using the following calculation formula.
[0026]
Specific gravity in wet state (g / cm^Three) = W₂/ [10- (W₁-W₂) / Γ]
[Exothermic reaction]
The reaction method of the present invention can be suitably used for a reaction that generates an exotherm of 0.1 to 3000 kcal / h / kg based on the amount of liquid in the reactor. In general, in an exothermic reaction, troubles due to local heat generation and side reactions are likely to occur in the portion where the heterogeneous catalyst or the reaction solution stays. Therefore, the present invention that can eliminate these problems is effective.
In the case of a reaction with a calorific value exceeding 3000 kcal / h / kg, if a stagnant part occurs during the separation of the heterogeneous catalyst particles and the reaction liquid, a partial high heat generation occurs, even if a cooling medium is used. In many cases, it cannot be heated. The partial heat generation causes inconveniences such as polymerizing the reaction product and shortening the life of the heterogeneous catalyst particles. According to the method of the present invention, there is no occurrence of a staying portion when the heterogeneous catalyst particles and the reaction liquid are separated, and these problems can be easily avoided. In particular, the above problem can be effectively avoided in a fluidized bed. In addition, the calorific value generated by the reaction can be predicted from the theoretical calorific value per mole of the main reaction raw material (based on the reaction raw material having the smallest molecular weight). When the calorific value is 5 to 50 kcal / mol, the reaction method of the present invention may be applied.
[0027]
Of course, even if the exotherm due to the reaction is less than 0.1 kcal / h / kg, the application of the present invention can reduce the residence of the heterogeneous catalyst and the reaction solution, which is effective for suppressing side reactions.
[Reaction method]
The method of the present invention is not particularly limited as long as it is a reaction method in which reaction is performed in a liquid phase using heterogeneous catalyst particles, and can be applied to various reaction methods. In particular, it is effective in a reaction that handles a material that is easily polymerized, for example, a reaction that generates (meth) acrylate.
[0028]
Specifically, for example, (meth) acrylic acid and alcohol are reacted to produce (meth) acrylate, or alkylene oxide and (meth) acrylic acid are reacted to produce hydroxyalkyl (meth) acrylate. It is preferable to use it for the reaction. This reaction for obtaining a hydroxyalkyl (meth) acrylate has a large calorific value during the reaction, and the polymerizability of the resulting hydroxyalkyl (meth) acrylate is very high. It is considered that the effect is great.
In order to make the present invention more effective, it is preferably handled in the presence of a general polymerization inhibitor or stabilizer. Such an additive is not particularly limited as long as it is a substance having an effect of preventing polymerization.
[0029]
<Reacting (meth) acrylic acid with alcohol
Reaction for generating (meth) acrylate>
Acrylic acid + methanol → methyl acrylate + water
Acrylic acid + ethanol → ethyl acrylate + water
Acrylic acid + n-butanol → n-butyl acrylate + water
Acrylic acid + 2-ethylhexanol → 2-ethylhexyl acrylate + water
Methacrylic acid + methanol → methyl methacrylate + water
In these reactions, a dehydration tower can be provided in a reactor or the like, and water can be removed to improve the reaction rate and selectivity.
[0030]

<Raw alcohol>
Methanol, ethanol, propanol, butanol, isobutanol, tertiary butyl alcohol, 2 ethylhexyl alcohol, and the like can be used.
[0031]
<Raw acid>
(Meth) acrylic acid is used.
<Raw material alkylene oxide>
Ethylene oxide, propylene oxide, butylene oxide, styrene oxide and the like can be used.
The reaction method of the present invention may be carried out in two or more stages. For example, the reaction rate after the reaction has progressed to a certain extent is withdrawn as described above, and the reaction rate after removal is further reacted in the same manner to improve the reaction rate and selectivity. Can do.
[0032]
[Reactor]
The reaction apparatus of the present invention is an apparatus used in the reaction using the heterogeneous catalyst particles. Both fixed bed reactors and fluidized bed reactors can be applied. A tank-type reactor having a stirrer and a drain line are provided. A linear screen having a solid-liquid separation function is disposed between the reactor and the drain line. The linear screen has a gap width that does not substantially allow the heterogeneous catalyst particles to pass through.
The linear screen is preferably attached to the side wall of the reactor so that the screen surface faces downward inside the reactor. In this way, by installing the screen surface downward, clogging by the heterogeneous catalyst particles can be effectively prevented.
[0033]
Furthermore, in the case of a fluidized bed reactor, it is preferable that the linear screen is installed so as not to greatly impede the flow of the slurry-like reaction liquid containing heterogeneous catalyst particles during solid-liquid separation.
The reaction apparatus of the present invention preferably includes a plurality of the liquid drain lines, and each liquid drain line is connected to the reactor via a separate linear screen.
By installing the linear screen in the flow path of the reaction liquid, the efficiency of solid-liquid separation is improved and troubles are reduced. The specific installation location is not particularly limited.
[0034]
For example, a nozzle may be attached to the bottom of the tank, and a linear screen may be embedded in the nozzle, or the linear screen may be attached in a form that protrudes from the nozzle. A plate-like screen can be attached to the bottom of the tank. It is also possible to attach a nozzle embedded in a line screen or partially protruding from the side of the tank. An extraction tube can be attached to the top of the tank, and a linear screen can be provided at the tip.
However, in the case of a fluidized bed reaction apparatus, if a linear screen is installed in a resin retention part, side reactions in the retention part proceed, and troubles due to solids such as polymers are likely to occur. Therefore, it is preferable to arrange a linear screen in a portion where the liquid flows by each stirring and circulation.
[0035]
When a linear screen is installed in the staying part, there is a demerit that the particles of heterogeneous catalyst adhere to the screen surface, and the differential pressure of filtration increases by that amount. The pressure does not increase. This is believed to be due to the fact that the heterogeneous catalyst particles are always washed away and do not accumulate on the surface. Troubles such as side reactions and polymerization due to retention of the heterogeneous catalyst are also eliminated.
If the liquid is in a fluid state, a soot that completely enters the tank is prepared with a linear screen, and a heterogeneous catalyst and a stirrer are placed in this soot and allowed to react with stirring.
[0036]
In the case of the fixed bed reactor, the basic structure is the same as that of the fluidized bed reactor. A similar technique can be applied to the structure of the linear screen. A linear screen can be placed to form a flat surface across the reactor. The line screen can be provided on the whole or a part of the cross section.
The arrangement of the linear screen is preferably set so that the flow is uniform with respect to the cross section perpendicular to the liquid flow direction in the reactor of the fixed bed reactor. For example, in the case of a cylindrical screen, 3 pieces / m with respect to a cross section perpendicular to the liquid flow direction.²The above should be arranged evenly. 3 / m²If the ratio is less than 1, it is not preferable because a liquid staying portion is generated in the catalyst layer, a polymer or the like is easily generated, the screen is clogged, and the reaction efficiency is lowered.
[0037]
The reactor of the fixed bed reactor is fixedly packed with a heterogeneous catalyst. The filling method and filling conditions of the heterogeneous catalyst can be performed in the same manner as in a normal reaction method.
The flow of the reaction liquid can be an upward flow from the lower side to the upper side of the reactor, or can be a downward flow from the upper side to the lower side. In the case of reactive distillation in which light boiling separation is performed, such as an esterification reaction or a transesterification reaction, an upward flow is preferable. Downflow is preferred to prevent clogging.
In the reactor, a relatively large diameter heterogeneous catalyst particle is disposed at a position adjacent to the linear screen, and a relatively small diameter heterogeneous catalyst particle is disposed at a position away from the linear screen. Can do. The relatively large-diameter heterogeneous catalyst particles hardly pass through the gaps in the linear screen. Relatively small heterogeneous catalyst particles have good reaction efficiency. The relatively large diameter heterogeneous catalyst functions as a screen that prevents the passage of relatively small diameter heterogeneous catalyst particles.
[0038]
When a flat linear screen is arranged on the bottom side of the reactor, the upper space of the linear screen is filled with relatively large-diameter heterogeneous catalyst particles at a certain depth, and the space above it is filled. It can be filled with non-uniform catalyst particles of relatively small diameter.
As the particle size ratio of the two types of heterogeneous catalyst particles, the particle size of the relatively small diameter heterogeneous catalyst particles may be set to about 0.8 times the particle size of the relatively large diameter heterogeneous catalyst particles. it can. The particle diameter of the relatively large diameter heterogeneous catalyst particles is set to 1.1 to 30 times the gap width of the linear screen, and the particle diameter of the relatively small diameter heterogeneous catalyst particles is set to 1 of the gap width of the linear screen. It can be set to 0 to 15 times.
[0039]
Furthermore, relatively large diameter particles having no catalytic function may be disposed at positions adjacent to the linear screen, and relatively small diameter non-uniform catalyst particles may be disposed on the outside thereof. As a specific example of the particles having no catalytic function, stainless steel or the like can be used.
In the reactor, on the side to which the reaction liquid is supplied, a dispersion plate such as a mesh can be arranged in order to prevent the backflow of the heterogeneous catalyst particles and to improve the dispersion of the reaction liquid. . The dispersion of the reaction liquid is preferably as uniform as possible with respect to the horizontal cross section of the packed bed of the heterogeneous catalyst.
[0040]
In the case of a downward flow, it is not always necessary to take measures against the backflow of the heterogeneous catalyst particles. At this time, the dispersion plate for improving the dispersion of the reaction liquid does not necessarily need to cover the entire surface. It may be a porous plate disposed on the entire surface or a part thereof, or may be an umbrella-shaped porous plate. It can also be kept relatively small for maintenance purposes. As long as the liquid is dispersed on the heterogeneous catalyst particles by applying a normal dispersion method, the shape and structure of the dispersion plate are not particularly limited.
[Specific example of reactor]
Below, the reaction apparatus of this invention used in reaction using the said ion exchange resin is demonstrated using drawing.
[0041]
<Fixed bed reactor (1)>
The reactor shown in FIG. 1 (a) is a fixed bed reactor.
The reactor 10 having a cylindrical shape with a circular cross section and closed at the upper and lower ends in a dome shape is provided with a supply port 12 for the reaction liquid 40 at the upper end, and a liquid outlet 14 for taking out the reaction liquid after the reaction at the lower end. have.
In the internal space of the reactor 10, a mesh-like dispersion plate 16 is disposed near the top, and a partition plate 18 is disposed near the bottom. The space between the dispersion plate 16 and the partition plate 18 is filled with heterogeneous catalyst particles 30. A solid-liquid separator 20 having a cylindrical line screen is disposed on the partition plate 18, and the reaction liquid 40 passes through the solid-liquid separator 20 and is sent to a space below the partition plate 18. Is done.
[0042]
The heterogeneous catalyst particles 30 are filled with heterogeneous particles 34 having a relatively large diameter at a constant depth near the partition plate 18 and the solid-liquid separator 20. The solid-liquid separator 20 is in a state where it is buried in the relatively large diameter non-uniform particles 34. A relatively small non-uniform particle 32 is filled above the relatively large non-uniform particle 34.
By supplying the reaction liquid 40 to the reactor 10 filled with the heterogeneous catalyst particles 30, the reaction liquid 40 is evenly spread over the entire surface of the reactor 10 by the dispersion plate 16, and descends in the reactor 10, The reaction occurs in the presence of the heterogeneous catalyst particles 30. The reaction liquid 40 after the reaction is separated from the heterogeneous catalyst particles 30 by the solid-liquid separator 20, and only the reaction liquid 40 is taken out from the liquid outlet 14.
[0043]
Without the dispersion plate 16, the reaction liquid 40 flows in a concentrated manner in the central portion of the reactor 10 immediately below the supply port 12, so that the proportion of the portion of the reactor 10 that is effectively used for the reaction decreases. The reaction performance is likely to deteriorate. In particular, the reaction solution 40 tends to stay in the peripheral portion near the upper end of the reactor 10, and polymerization and side reactions are likely to occur. In order to solve such a problem, the installation of the dispersion plate 16 is effective.
In addition to the mesh-like dispersion plate 16 shown in FIG. 1 (a), a perforated plate-like dispersion plate may be used, or as shown in FIG. 1 (b), an umbrella-like dispersion plate 17 is provided directly below the supply port 12. It can also be installed. A plurality of dispersing means can be installed in combination.
[0044]
In addition to the structure in which only one supply port 12 is arranged directly above the reactor 10, a plurality of supply ports 12 can be arranged dispersed throughout the planar shape of the reactor 10. .
Further, as shown in FIG. 1 (c), a liquid passage port 15 consisting of a short pipe or a through hole is provided at a plurality of locations of a dispersion pipe 13 which is connected to the supply port 12 inside the reactor 10 and has an annular shape as a whole. If it is provided, the reaction liquid 40 can be distributed and supplied evenly in the circumferential direction.
Although not shown, if the same pipe as the above-described dispersion pipe 13 is provided near the liquid outlet 14 at the bottom of the reactor 10, the reaction liquid 40 that has passed through the solid-liquid separator 20 is converted into the reactor. It can be collected evenly from the entire circumference of 10 and sent to the liquid outlet 14.
[0045]
2 and 3 show the detailed structure of the solid-liquid separator 20.
A wire 22 constituting a linear screen is supported in a cylindrical state by being wound spirally. Support members 24 and 26 are arranged above and below the cylindrical wire 22. Upper and lower support members 24 and 26 are supported by support bolts 28 penetrating the center. The solid-liquid separator 20 is attached by fixing the support member 26 to the partition plate 18.
As shown in FIG. 3, the spirally wound wire 22 is disposed with a gap 21 between adjacent portions of the wire 22, disposed on the inner peripheral side of the wire 22, and supported vertically. It is attached to a support shaft 23 supported by the members 24 and 26. The cross-sectional shape of the wire 22 is approximately an isosceles triangle, a wide base is disposed on the outer peripheral side, and a vertex is disposed on the inner peripheral side.
[0046]
When the reaction liquid 30 containing the heterogeneous catalyst particles 30 tries to pass through a cylindrical linear screen composed of the wire 22, the heterogeneous catalyst particles 30 having a particle size larger than the width W of the gap 21 between the wires 22. Is prevented from passing, and only the reaction solution 40 passes, and the solid-liquid is separated.
In FIG. 2, the lower end of the linear screen constituted by the wire rod 22 is disposed at a position lower than the partition plate 18 inside the support member 26. As a result, the reaction liquid 40 can be reliably passed to the upper surface position of the partition plate 18 and solid-liquid separation can be performed. It is difficult for the reaction liquid 40 to stay near the upper surface of the partition plate 18.
[0047]
The lower end of the linear screen, that is, the wire rod 22 can be disposed at the same position as or below the upper surface of the partition plate 18 or can be disposed at a position slightly higher than the partition plate 18. However, it is preferable to set the structure of the solid-liquid separator 20 so that the reaction liquid 40 does not stay as much as possible above the partition plate 18. For example, the distance between the lower end of the linear screen and the upper surface of the partition plate 18 is preferably set to 15 mm or less.
The fixed bed reactor shown in FIG. 4 differs from the above embodiment in the structure of the solid-liquid separator 20.
[0048]
Near the bottom of the reactor 10, a solid-liquid separator 20 consisting of a flat linear screen is arranged over the entire surface of the horizontal cross section. As shown in FIG. 4 (b), a large number of wires 22 are arranged in parallel in the cross section of the reactor 10 with gaps 21 between them. The cross-sectional shape of the wire 22 is the same as that of FIG. 3, and the wide bottom surface side is arranged at the upper part and the apex side is arranged at the lower part. Many wire rods 22 are supported by a support shaft 23 arranged on the back side.
In the above embodiment, the entire cross section of the reactor 10 performs the solid-liquid separation function, and efficient solid-liquid separation can be performed.
[0049]
<Fluidized bed reactor>
The reactor shown in FIG. 5 is a fluidized bed reactor.
The basic structure of the reactor 50 is the same as that of the fixed bed reactor described above. Although not shown in the figure, a supply port for the reaction liquid 40 is provided in the upper part of the reactor 50.
A stirrer 52 that is rotationally driven by a motor or the like is provided inside the reactor 50. A heating / cooling jacket 54 for heating or cooling is provided on the outer periphery of the lower portion of the reactor 50.
On the lower side surface of the reactor 50, the solid-liquid separator 20 accommodated in the accommodating cylinder 58 is attached. The solid-liquid separator 20 composed of a cylindrical line screen is connected to a liquid discharge pipe 56 connected to a flange plate 59 that closes the end surface of the storage cylinder 58.
[0050]
Most of the solid-liquid separator 20 is disposed inside the storage cylinder 58, and a part of the tip protrudes inside the reactor 50 inside the storage cylinder 58.
As shown in FIG. 5 (b), a plurality of storage cylinders 58 and solid-liquid separators 20 are installed, which are arranged in the radial direction in the horizontal section of the reactor 50, and the radial direction. Some are arranged in a tilted direction.
In the fluidized bed reaction apparatus, the reaction liquid 40 and the heterogeneous catalyst particles 30 supplied to the upper part of the reactor 50 are stirred by a stirrer 52 to react in a fluid state.
A part of the reaction solution 40 is extracted to the liquid discharge pipe 56 through the solid-liquid separator 20. At this time, since the heterogeneous catalyst particles 30 dispersed in the reaction liquid 40 cannot pass through the gaps 21 of the wire 22 constituting the cylindrical screen of the solid-liquid separator 20, only the reaction liquid 40 is separated and taken out. .
[0051]
The embodiment shown in FIG. 6 is different from the embodiment in the mounting structure of the solid-liquid separator 20.
In FIG. 6 (a), the tip of the solid-liquid separator 20 accommodated in the accommodating cylinder 58 is arranged inside the inner peripheral wall of the reactor 50.
In FIG. 6 (b), the tip of the solid-liquid separator 20 protrudes greatly inward from the housing cylinder 58. In addition, a linear screen made of the wire 22 is provided only at the length L portion on the front end side of the solid-liquid separator 20.
6C, in the structure of FIG. 6B, the base side of the solid-liquid separator 20 is extended to the outer periphery so that the gap between the housing cylinder 58 and the solid-liquid separator 20 is minimized. Yes. With such a structure, retention of the reaction liquid and heterogeneous catalyst particles between the storage cylinder 58 and the solid-liquid separator 20 can be eliminated, and generation of a polymer and side reaction can be prevented. A packing material made of Teflon (trade name, fluorine resin) or the like may be placed in the gap between the housing cylinder 58 and the solid-liquid separator 20.
[0052]
In the embodiment shown in FIG. 7, the solid-liquid separator 20 is arranged at the center of the bottom surface of the reactor 50.
In FIG. 7 (a), the solid-liquid separator 20 is arranged upward in the center of the bottom surface of the reactor 50. In FIG. 7 (b), the solid-liquid separator 20 is accommodated in an accommodating cylinder 58 that projects downward from the center of the bottom surface of the reactor 50. In FIG. 7 (c), the solid-liquid separator 20 is disposed around the bottom surface of the reactor 50, a part of the solid-liquid separator 20 is disposed in the storage cylinder 58 and the remaining part is disposed in the internal space of the reactor 50. Has been. The linear screen made of the wire 22 is disposed above the housing cylinder 58. The lower part of the solid-liquid separator 20 is thickly extended so that a large gap is not formed between the solid-liquid separator 20 and the inner surface of the housing cylinder 58. With this structure, the length of the solid-liquid separator 20 is not particularly limited, and may be extended to near the liquid level, for example.
[0053]
【Example】
EXAMPLES Examples and comparative examples according to the present invention will be described below, but the present invention is not limited to the examples.
(Fixed bed reaction)
<Example 1>
Methyl acrylate production reaction was carried out using a fixed bed reactor.
Product: Methyl acrylate
Ingredients: acrylic acid, methanol
Reactor: fixed bed reactor (see Fig. 1), diameter 1400mm, height 2300mm, straight barrel capacity 3.5m^Three, Resin charge 2.0m^Three
Solid-liquid separator: Johnson screen (trade name: sold by JGC Universal Co., Ltd.), cylindrical type, effective filtration part (linear screen) is placed up to 10mm below the partition plate (see Fig. 2), Outer diameter 50mm, effective length 170mm, wire rod width 1.5mm, gap width 0.3mm, installation number 20 (13.0 / m²), Effective filtration area 0.534m²(0.027m²/ Piece), opening area 0.089m²(0.0044m²/Pieces)
Passing liquid volume: Passing liquid volume 1.67m^Three/ H, liquid density 900 kg / m^Three, Effective filtration area passage speed 0.87mm / s, opening part passage linear velocity 5.2mm / s, downward flow from top to bottom of reactor
Heterogeneous catalyst: Diaion PK-208 (trade name: manufactured by Mitsubishi Chemical Corporation, porous type cation exchange resin based on para-toluenesulfonic acid, 50% particle size = about 700 μm, 15% particle size = about 500 μm
-Implementation results-
Reactor inlet composition: main raw material (acrylic acid) 50%, auxiliary raw material (methanol) 20%, product (methyl acrylate) 15%, water 5%
Reactor outlet composition: main raw material (acrylic acid) 30%, auxiliary raw material (methanol) 5%, product (methyl acrylate) 40%, water 10%, impurities 15%
Conversion 35-40%
100 hours later: No operational problems
After 1000 hours: No problem with heterogeneous catalyst particles. There is almost no polymer adhesion. A trace amount of polymer adhered to the support structure of the linear screen, but could be easily removed.
[0054]
<Example 2>
In Example 1, the Johnson screen of the solid-liquid separator used had a structure in which the linear screen portion was arranged 15 mm above the partition plate. There is a space between the lower end of the linear screen and the surface of the partition plate, and the reaction liquid stays on the partition plate a little.
-Implementation results-
After 1000 hours of reaction, there was polymer adhesion on the support structure of the linear screen. Slight clogging occurs in half of the wires. However, it could be removed by jet cleaning. Some wire rods were brush cleaned.
[0055]
<Example 3>
Production reaction of methyl methacrylate was carried out. Description of the conditions common to the first embodiment will be omitted.
Product: Methyl methacrylate
Ingredients: methacrylic acid, methanol
Reactor: Fixed bed reactor (see Fig. 1), diameter 1800mm, height 2500mm, used in full liquid state.
Solid-liquid separator: Johnson screen (trade name: sold by JGC Universal), cylindrical screen outer diameter 60mm, effective length 170mm, element (wire) width 1.5mm, gap width 0.15mm, installation number 20 (4.8 pieces / m²), Effective filtration area 0.64m²(0.032m²/ Piece), opening area 0.058m²(0.0029m²/Pieces)
Passing liquid volume: Passing liquid volume 3.00m^Three/ H, liquid density 900 kg / m^Three, Effective filtration area passage speed 1.30mm / s, opening part passage linear speed 14mm / s
Heterogeneous catalyst: Same as Example 1.
[0056]
-Implementation results-
Reaction temperature: 70 ° C
Reactor inlet composition: main raw material (methacrylic acid) 61%, auxiliary raw material (methanol) 9%, product (methyl methacrylate) 27%
Reactor outlet composition: main raw material (methacrylic acid) 45%, auxiliary raw material (methanol) 3%, product (methyl methacrylate) 46%
The reaction temperature was manipulated so that the conversion was 25%.
After 4 months: The reaction temperature was 79 ° C., which was confirmed to be effective in extending the life of the heterogeneous catalyst particles as compared with Example 4. Heterogeneous catalyst particles can be operated continuously for 4 months with no operational problems. There is almost no polymer adhesion. A trace amount of polymer adhesion could be easily removed from the support structure of the linear screen.
[0057]
<Example 4>
In Example 3, the solid-liquid separator was changed to the structure of Example 2. Specifically, as the Johnson screen of the solid-liquid separator, the one having a structure in which the linear screen portion is disposed 15 mm above the partition plate is used.
-Implementation results-
Reaction temperature: 70 ° C
Reactor inlet composition: main raw material (acrylic acid) 61%, auxiliary raw material (methanol) 9%, product (methyl acrylate) 27%
Reactor outlet composition: main raw material (acrylic acid) 45%, auxiliary raw material (methanol) 3%, product (methyl acrylate) 45%
After 4 months: Reaction temperature 83 ° C. Heterogeneous catalyst particles can be operated continuously for 4 months with no operational problems. The polymer adheres to the support structure of the linear screen. Slight clogging occurs in half of the wires. However, it could be removed by jet cleaning. Some wire rods were brush cleaned.
[0058]
<Example 5>
In Example 3, the filling conditions of the heterogeneous catalyst particles were changed. Description of the conditions common to the third embodiment will be omitted.
Specifically, the heterogeneous catalyst particles were classified and divided into a large part (5% of the whole) having a particle diameter of 700 to 1200 μm and a small part (95% of the whole) having a particle diameter of 300 to 700 μm. As shown in FIG. 1, after filling the large particle portion 34 to a position slightly higher than the solid-liquid separator 20 on the bottom side of the reactor 10, the small particle portion 32 was filled thereon.
-Implementation results-
After 4 months: reaction temperature 77 ° C. Heterogeneous catalyst particles can be operated continuously for 4 months with no operational problems. There is almost no polymer adhesion. A very small amount of attached polymer could be easily removed.
[0059]
<Comparative Example 1>
In Example 2, the same conditions were employed except that a wire mesh strainer was used for the solid-liquid separator.
Solid-liquid separator: A wire mesh strainer, a cylinder, 50 mesh, and a filtration effective part are arranged 15 mm above the partition plate.
-Implementation results-
After 100 hours: The reaction rate and selectivity decreased with time, and the pressure loss tended to increase.
[0060]
Since the operation became difficult in about 500 hours, when the inspection was performed, fine particles of heterogeneous catalyst particles were clogged in the strainer mesh. There was much adhesion of viscous material and polymer. It was necessary to change the mesh. The polymer also adhered to the support structure of the strainer.
[Fluidized bed reaction]
<Example 6>
A production reaction of 2-ethylhexyl acrylate was performed using a fluidized bed reactor.
[0061]
Product: 2-ethylhexyl acrylate
Ingredients: acrylic acid, 2-ethylhexanol
Reactor: Fluidized bed reactor (see FIG. 5), with dehydration packed tower 100φ, diameter 500 mm, stainless steel 100 liter, charge [reaction liquid + heterogeneous catalyst particles 70 liters, heterogeneous catalyst particles 18 liters (dry state) ] Jacket heating / steaming.
Solid-liquid separator: Johnson screen (trade name: sold by JGC Universal Co., Ltd.), cylindrical type, attached to the bottom outer periphery of the reactor, cylindrical screen outer diameter 34mm, effective length 60mm, element (wire) width 1.5mm , Gap width 0.15mm, installation number 1 (3.1 / m²), Effective filtration area 0.0064m², Opening area 0.00058m²The solid-liquid separator with the structure shown in Fig. 6 (c) is rotated 90 ° and installed in an upward position.
[0062]
Passing liquid volume: Passing liquid volume 0.039m^Three/ H, liquid density 900 kg / m^ThreeEffective filtration area passage speed 3.17 mm / s, opening portion passage linear velocity 18 mm / s, downward flow from the top to the bottom of the reactor.
Stirrer: Foudra blade, blade diameter ratio 0.7, blade tip speed 4m / s
Heterogeneous catalyst: Same as Example 1.
-Implementation results-
Reactor pressure: 70 mmHg
Reactor inlet composition: main raw material (acrylic acid) 49%, auxiliary raw material (2 ethylhexanol) 35.6%, product (2 ethylhexyl acrylate) 14.2%, water 0.1%. 23.5 kg / h of alcohol and 13.2 kg / h of alcohol were fed to the reactor from the top, and 0.05% phenothiazine was charged from the top to the main raw material.
[0063]
Composition at outlet of reactor: 13.2% main raw material (acrylic acid), 25.7% secondary auxiliary material (2-ethylhexanol), 59.6% product (2-ethylhexyl acrylate), 0.4% water, and the reaction liquid was 34 0.8 kg / h. In the distillation tank, an aqueous phase of 1.7 kg / h and an oil phase of 0.18 kg / h were extracted.
Conversion: 60% for acrylic acid, 58% for alcohol
Selectivity: 98.4% for acrylic acid, 98.5% for alcohol
Impurities: Dimer acid 2-ethylhexyl 0.26%, etc.
Inspection after 150 hours, no polymer.
[0064]
After 1000 hours: Resin was clogged in the screen gap. No polymer adhesion. no problem.
<Example 7>
A production reaction of hydroxypropyl acrylate was carried out.
Product: Hydroxypropyl acrylate
Ingredients: acrylic acid, propylene oxide
Reactor: Same as Example 6 except that 48 liters (wet state) of heterogeneous catalyst particles were charged and cooled by flowing cold water through the jacket.
[0065]
Solid-liquid separator: Johnson screen (trade name: sold by JGC Universal Co., Ltd.), cylindrical type, attached to the reaction fluid flow part at the bottom outer periphery of the reactor (see Fig. 6 (b)), cylindrical screen outer diameter 34mm, Effective length 30mm, element (wire) width 1.5mm, gap width 0.15mm, installation number 1 (3.1 / m²), Effective filtration area 0.0032m², Opening area 0.00029m².
Passing liquid volume: Passing liquid volume 0.031m^Three/ H, liquid density 900 kg / m^ThreeThe effective filtration area passage speed is 2.7 mm / s, and the aperture passage linear speed is 30 mm / s.
Stirrer: Same as Example 6.
[0066]
Heterogeneous catalyst: Diaion PK-316 (trade name: manufactured by Mitsubishi Chemical Corporation, amine-based anion exchange resin, 50% particle size = about 700 μm, 15% particle size = about 450 μm)
-Implementation results-
Reaction temperature: 80 ° C
Reactor inlet composition: 45% by weight of main raw material (acrylic acid), 55% by weight of auxiliary raw material (propylene oxide).
Retention time: Raw material is charged to 1 hour.
Conversion: 80%
100 hours later: No abnormality
After 1000 hours: No polymer adhesion
<Example 8>
Solid-liquid separation was performed using 2-hydroxyethyl acrylate.
[0067]
Reactor: The same as in Example 7 except that the capacity is 20 liters made of stainless steel and 60% of the heterogeneous catalyst is charged.
Solid-liquid separator: the same as in Example 7.
Passing liquid volume: Passing liquid volume 0.0095m^Three/ H, liquid density 1050 kg / m^Three.
Stirrer: Paddle (3 sheets), blade diameter ratio 0.4, blade tip speed 1.5 m / s.
Heterogeneous catalyst: Same as Example 7.
-Implementation results-
Operating temperature: 60 ° C
100 hours later: No abnormality
After 1000 hours: No abnormality, stable operation, no clogging.
[0068]
<Comparative Example 2>
In Example 6, the same conditions were employed except that an 80-mesh wire mesh was used for the solid-liquid separator.
Solid-liquid separator: An 80-mesh wire mesh (diameter: 100 mm) was attached to the extraction tube at the bottom of the reactor. Mesh wire rod width 0.15mm, gap width 0.17mm, aperture ratio 25%, effective filtration area 0.0079m², Opening area 0.00196m².
Passing liquid volume: Passing liquid volume 0.039m^Three/ H, liquid density 900 kg / m^Three, Effective filtration area passage speed 1.4 mm / s, opening portion passage linear velocity 5.5 mm / s (down flow from the upper part to the lower part of the reactor.
[0069]
Stirrer, heterogeneous catalyst: Same as Example 6.
-Implementation results-
After 150 hours, the resin was clogged and the differential pressure tended to increase, so the operation was stopped and the inspection was performed.
The mesh was clogged with heterogeneous catalyst. Moreover, there were many cloggings due to polymer adhesion. It was necessary to restore the solid-liquid separator after washing it sufficiently.
<Comparative Example 3>
Similar to Comparative Example 2, the same conditions as in Example 6 were adopted except that an 80-mesh wire mesh was used for the solid-liquid separator.
[0070]
Solid-liquid separator: An 80-mesh wire mesh (diameter: 100 mm) was formed into a cylindrical shape and attached to the outer periphery of the bottom of the reactor. The mounting position is outside 50% of the blade diameter of the agitator. Cylindrical mesh outer diameter 34 mm, effective length 60 mm, mesh wire width 0.15 mm, gap width 0.17 mm, installation number 1 (3.14 pieces / m²), Effective filtration area 0.0064m², Opening area 0.00016m².
Passing liquid volume: Passing liquid volume 0.039m^Three/ H, liquid density 900 kg / m^ThreeEffective filtration area passage speed 1.7 mm / s, opening portion passage linear velocity 7 mm / s, downward flow from the top to the bottom of the reactor.
[0071]
Stirrer, heterogeneous catalyst: Same as Example 6.
-Implementation results-
After 500 hours: Resin was clogged up slightly in the mesh. Since there was a small amount of polymer adhesion, washing was performed.
<Comparative example 4>
The same production reaction as in Example 7 was carried out by combining a reactor and a sedimentation tank.
The reactor was not provided with a solid-liquid separator, and the slurry liquid of the reaction liquid and heterogeneous catalyst particles extracted from the reactor was sent to a weight sedimentation tank having a height of 40 mmφ × 100 mm, and the supernatant liquid was extracted. The settling tank was also cooled with a cooling jacket (circulated at 1 liter / hour).
[0072]
-Implementation results-
After 3 hours, a tendency to increase the temperature of the settling tank was observed. The circulation pump was abnormal and stopped. The polymer and solidified heterogeneous catalyst were found in the settling tank.
[0073]
【The invention's effect】
According to the present invention, in the reaction method using a heterogeneous catalyst, side reactions and polymerization are prevented during separation of the heterogeneous catalyst particles and the reaction liquid, and unstable operation due to clogging of the heterogeneous catalyst particles is avoided. However, separation of the heterogeneous catalyst particles and the reaction liquid can be reliably and efficiently performed using a compact apparatus.
In particular, the linear screen that separates the heterogeneous catalyst particles and the reaction liquid has a sufficiently wide gap in the length direction compared to the width direction. Is less likely to inhibit Further, even in a reaction in which a polymer having a high viscosity or adhesion is generated, the gap between the linear screens is less likely to be clogged or adhered.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view (a) of a fixed bed reactor representing an embodiment of the present invention and a cross-section of a main part (b) (c)
[Fig.2] Enlarged sectional view of the solid-liquid separator
FIG. 3 is an enlarged sectional view of a linear screen.
[Fig. 4] Vertical sectional view (a) and horizontal sectional view (b) of fluidized bed reactor
FIG. 5 is a schematic structural diagram (a) and a horizontal sectional structural diagram (b) showing another embodiment.
FIG. 6 is a schematic structural diagram showing another embodiment.
FIG. 7 is a schematic structural diagram showing another embodiment.
[Explanation of symbols]
10, 50 reactor
12 Supply port
14 Liquid outlet
15 Fluid inlet
16 Dispersion plate
18 Partition plate
20 Solid-liquid separator
21 Clearance
22 Wire
30 Heterogeneous catalyst particles
40 reaction liquid
52 Stirrer

Claims (7)

A cylindrical reactor having a circular cross section, and a cylindrical screen formed by spirally winding wire rods and having a gap width that does not substantially allow non-uniform catalyst particles to pass through, The linear screen is placed on the partition plate arranged at the bottom of the space for filling the heterogeneous catalyst particles in the reactor so that the gap between the gap through which the reaction solution passes and the top surface of the partition plate is 5 mm or less. A method in which a reaction is performed by using a fixed bed reactor arranged and passing the reaction liquid from the upper part to the lower part of the reactor packed with heterogeneous catalyst particles, and the heterogeneous catalyst is placed in the reactor. A step of filling particles (-a), a step of reacting the reaction solution supplied to the reactor in the presence of the heterogeneous catalyst particles, and a post-reaction including the heterogeneous catalyst particles passing the reaction mixture from the outside of the linear screen inward A step (b) for extracting the reaction solution separated from the heterogeneous catalyst particles from the reactor, and in the step (-a), the position adjacent to the linear screen on the upstream side has a relatively large diameter. A reaction method using a heterogeneous catalyst, characterized in that a heterogeneous catalyst particle having a relatively small diameter is arranged at a position away from the linear screen. As before Symbol linear screen than it said 15% particle diameter of the heterogeneous catalyst particle is used one having a small gap width, the reaction method using a heterogeneous catalyst according to claim 1. The wire of the cylindrical screen Ru der having an inner peripheral side is narrow tapered cross section thicker outer peripheral side of the tubular screen, a reaction method using a heterogeneous catalyst according to claim 1 or 2. The reaction method using the heterogeneous catalyst according to any one of claims 1 to 3 , wherein ion-exchange resin particles having an average particle diameter of 0.1 to 3 mm are used as the heterogeneous catalyst particles. The reaction method using a heterogeneous catalyst according to any one of claims 1 to 4 , wherein the reaction is a reaction in which an alkylene oxide and (meth) acrylic acid are reacted to produce a hydroxyalkyl (meth) acrylate. . The reaction method using the heterogeneous catalyst according to any one of claims 1 to 4 , wherein the reaction is a reaction in which (meth) acrylic acid is reacted to form (meth) acrylate. A fixed bed reactor used in the reaction method according to any one of claims 1 to 6 , wherein a tank reactor having a circular cross section in which heterogeneous catalyst particles and a reaction liquid are accommodated, and the reactor Is connected between the drain line for taking out the reaction liquid after the reaction, the reaction liquid storage space of the reactor and the liquid drain line, and has a gap width that does not substantially allow the passage of the heterogeneous catalyst particles. A non-uniform catalyst having a relatively small diameter at a position distant from the linear screen. A fixed bed reactor characterized by arranging particles.

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